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Description of substance: Colorless liquid or crystals with a sour, vinegar-like odor.

LEL: 4.0% (10% LEL, 4,000 ppm)

Original (SCP) IDLH: 1,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty [1963] that Ghiringhelli and DiFabio [1957] determined a 1-hour LC50 of about 5,000 ppm for guinea pigs and mice. AIHA [1972] reported that 1 of 6 rats died following a 4-hour exposure to 16,000 ppm [Smyth et al. 1951]. However, the Standards Completion Program Respirator Committee felt that a worker might have difficulty escaping from 5,000 ppm due to the irritation effects, and reduced the IDLH to 1,000 ppm to allow escape without injury. According to AIHA [1972], workers have repeatedly sustained exposures up to about 200 ppm.

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA

Lethal concentration data:

Adjusted

LC50

LCLo

0.5-hr

Derived

Species

Reference

(ppm)

(ppm)

Time

LC (CF)

Value

Mouse

Ghiringhelli and DiFabio 1957

5,620

-----

1 hr

7,025 ppm (1.25)

703 ppm

Rat

Smyth 1956

16,000

-----

4 hr

32,000 ppm (2.0)

3,200 ppm

Other animal data: RD50 (mouse), 163 ppm [DeCeaurriz et al. 1981].

Human data: Marked irritation of the eyes, nose, and upper respiratory tract which could not be tolerated for more than 3 minutes was noted at 816 to 1,226 ppm [von Oettingen 1960]. It has been reported that 50 ppm or more is intolerable to most persons due to intense lacrimation and irritation of the eyes, nose, and throat [AIHA]. It has also been stated that repeated exposures to high concentrations may produce respiratory tract irritation with pharyngeal edema and chronic bronchitis [AIHA 1972].

Revised IDLH: 50 ppm

Basis for revised IDLH: The revised IDLH for acetic acid is 50 ppm based on acute inhalation toxicity data in humans [AIHA 1972].